This invention relates to a water entry preventing structure for an inboard/outboard motor and more particularly to an improved arrangement for preventing the entry of water into the flywheel housing of an inboard/outboard drive.
One widely used form of marine propulsion system is the "inboard/outboard" drive in which an internal combustion engine is mounted within the hull of the watercraft and the watercraft is propelled by a propulsion unit that is mounted outside of the hull and driven by the engine by means including an input shaft that extends through the transom of the hull. In accordance with such arrangements, it is the normal practice to provide some form of elastic coupling between the output shaft of the engine and the input shaft of the outboard drive propulsion unit so as to accommodate for angular misalignments and so as to permit movement of the engine to absorb vibrations by its resilient support. These flexible couplings are normally positioned in proximity to adjacent the flywheel of the engine so as to provide damping at the desired location.
Although this type of arrangement is particularly satisfactory, it is the normal practice to provide a flywheel housing that encircles the flywheel but which has a relatively large opening that is positioned in proximity to the flexible coupling and normally encircles it. Because of the large diameter of the opening in the flywheel cover, there is the likelihood that water may enter into the flywheel cover. The large diameter of the opening places its lower peripheral edge quite low in the watercraft and hence it is prone to the likelihood of bilge water entering it. In addition, the large clearance normally provided around the flexible coupling and its large diameter also aggravates the problem of water entry.
When water enters the flywheel housing, it can become engaged with the teeth of the starter gear mechanism and will be thrown by the rotation of the flywheel into proximity with the starter of the engine. The water can readily cause corrosion of the starter which can render its operation either difficult or, in extreme instances, inoperative.
It is, therefore, a principal object of this invention to provide an improved driving arrangement for an inboard/outboard drive that will preclude the entry of water into the flywheel housing.
It is a further object of this invention to provide an improved arrangement for reducing the likelihood of water entry into the flywheel housing of a marine propulsion unit.
It is yet another object of this invention to provide a drive arrangement for an inboard/outboard drive wherein the flexible coupling for the drive is positioned and sealed in such a way relative to the flywheel housing so as to insure against the entry of water into the flywheel housing.